Arc-lamp electrode.



' 16o Drawing.

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EMILE J. GUAY, F LYNN, MASSACHUSETTS, ASSIGNOR T0 GENERAL ELECTRIC I COMPANY, A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Application filed June 26, 1909. Serial No. 504,529.

Patented July 25, 1 15. 11.

To all whom it may concern:

Be it known that 1, Emma J. Gear, a citi zen of the United States, residing at Lynn, county of Essex, State of llllassachusetts, have invented certain new and useful lmproven'ients in Are Lamp Electrodes, of which the following is a specification.

My invention has reference to improvements in electrodes for are lamps, and it is applicable more particularly to are lamp electrodes in which titanium carhid is either the sole ingredient or in which this material is used as one of the ingredients in a composite electrode; and the object of the in vention is to reduce the spitting of such electrodes and to prevent. the adherence to the lamp g lobe of such particles which are still thrown off. This objectis secured by addlog to the electrode material an ingredient or ingredients which in the arc fuse with-the carbid to a composition, which in the fused or hot state does not adhere to glass.

It has been found that the utility of electrodes containing a considerable percentage of titanium carbid is considerably impaired by the fact that in its use fused particles of the titaniumcar-bid or of tho'titai'iium carbid. composition are thrown oil from the arc ing end of the electrode and are projected against the inc-losing globe, which, being made of glass, is fused slu'ierticially at the points where the hot carbid particles come in contact with the same, and that these particles then stick to the glass. By the con- ,,tinued use of the electrode this spitting of the electrode and the adherence of the projected particles to the glass gradually impairs the transparency of the glass globe, so that after a comparatively short time the lobe intercepts so much light that it has to e renewed. It. has been found that the globe cannot be cleansed by any mechanical means nor etilciently by any chemical means, and the object of my invention is to avoid the adherence of the projected particles of hot titanium carbid or titanium carbid CUIU- pounds to the glass.

I have discovered that by the addition ot' .a small percentage oil certain materials, particularly the elements belonging to e sulfur group-, to the titanium carb'ld, cor sounds are formed atv the arcing end which in a ployed.

measure diminish the spitting of the electrode, while the particles which are still thrown oil and projected against the inner Walls of the globe do not fuse or adhere to the glass, but roll off the same to the bottom 7 where they collect when the bottom is closed or drop out when the bottom is open. In

thereof. The range of percentages of sulfur that may be used is rather wide. I have found that the addition of one per cent. of tree sulfur to the body or" the titanium carbid electrode perceptibly reduces the amount of projected particles that adhere to the glass and that the addition of six per cent. of free sulfur to the titanium car-bid electrode is admissible; but .i'. the best result is obtained by the addition of four and one-half per cent. of free sulfur to the titanium cal-bid electrode body. Selenium or telluriuln, or mixtures of two or all three of the elements of the sulfur group, may be used Within the same range of percentages.

I desire it to be miderstood that the term titanium car-bid electrode as herein used is designed to cover any electrode in which titanium carbid is present to a suliicient extent to give to the arc theltitanium characteristics. This includes electrodes made en tirely of titanium car-bid and also electrodes in the formation oi. which, in addition to titanium carbid, other-materials are cm- The percentages of sulfur herein before referred to are percentages with relierence to the titanium carbid present in the electrode. The free sulfur, or selenium, or tellurium, is, in accordance with my invention, incorporated in the electrode by intimately mixing the finely divided sulfur, etc,

have found that with the finely divided titanium cal-bid and the other materials that may be employed in the formation of the electrode body and then forming the electrode in any of the ordinary, usua1,-or well-known Ways.

What I claim as new and desire'te secure by Letters Patent of the United States, is

1. A titanium earbid electrode containin a material which fuses With titanium carbi to a compound which in the hot state is nonadherent to glass.

A titanium earbid electrode containing one or more free elements of the sulfur group.

3.'A titanium cal-bid electrode containing between one and six per cent. of one or more of the free elements of the sulfur group.

4. A titanium carbid electrode containing between one and six per cent-of free sulfur.

5. A titanium carbid electrode containing 20 EMILE J. GUAY.

-W'itnesses:

BENJAMIN B. HULL, HELEN ORFORD. 

